WO1994002366A1

WO1994002366A1 - Pallet

Info

Publication number: WO1994002366A1
Application number: PCT/FI1993/000298
Authority: WO
Inventors: Kari Eerik Rantanen
Original assignee: Wisapak Oy AB
Current assignee: Wisapak Oy AB
Priority date: 1992-07-16
Filing date: 1993-07-15
Publication date: 1994-02-03
Anticipated expiration: 1995-01-16
Also published as: FI93933B; FI93933C; FI923261A0; LV11152A; LTIP793A; LT3490B; FI923261L; LV11152B

Abstract

The invention relates to a pallet (1) manufactured of recyclable cardboard. The pallet (1) consists of beams (3) attached crosswise in two layers above which a covering sheet (2) of cardboard can be provided. According to the invention the beams (3) are formed of parallel, tube-like board core pieces (4) which are surrounded by a sheet of corrugated cardboard (6). The axes of the core pieces (4) are perpendicular to the level of the pallet (1). Glue which is separated in the manufacturing process of recycled pulp is used for assembling the beams (3) and attaching the beams and the covering sheet (2) to each other to form the pallet (1). The material of the pallet is recycled into said manufacturing process or recycled pulp after use.

Description

PALLET

The object of this invention is a pallet which is manufactured mainly of recycleable cardboard using pieces of tube-like board cores which are situated in the pallet so that their axes are perpendicular to the level of the pallet. The purpose of the cardboard is to make it possible to recycle the material after use.

Pallets are traditionally made of wood which gives them a high load-carrying capacity. A wooden pallet can generally be used several times but in practice the pallets end up in waste dumps very quickly.

It is also well-known to manufacture the pallet from cardboard which can be recycled to the manufacturing of recycled pulp after use. This avoids waste problem caused by the pallets. However, a drawback with most pallets made of cardboard is that they do not have the same strength and load-carrying capacity as wooden pallets.

Published specification SE 356 994 discloses a disposable pallet which is manufactured of pieces of tube-like board cores. The cores are placed side by side against each other over the whole area of the pallet. The pallet is provided with legs so that the cores are of mutually different sizes. The cores, which are perpendicular to the level of the pallet, give the pallet load- carrying capacity but the problem of the solution is that the assembly of the pallet is troublesome.

The purpose of this invention is to form from pieces of board cores a cardboard pallet which has high load-carrying capacity and which is stronger than before and simpler to manufacture than previously known cardboard pallets. The pallet according to the invention is characterized in that it comprises beams formed of parallel tube-like board cores and the cardboard surrounding them which are provided in the pallet and attached to each other crosswise in two overlapping layers. The pallet according to the invention is fully made of recyclable material and it is primarily meant for disposable use, even though it can be used more depending on the purpose.

The board cores utilized in the pallet according to the invention are generally used as cores of paper rolls. The cores are manufactured by glueing layers of board, which are twisted spirally, on top of each other into a tube having a thick jacket formed of numerous layers of board. Recyclable pulp is typically used for the board cores. These types of cores made of recyclable material comprise high compression strength in the axial direction which is used in the pallet to provide the necessary load-carrying capacity for the pallet. According to the invention the cores, which can also consist of waste material which has been used previously, are chopped into fairly short pieces and arranged into a line and surrounded by cardboard so that elongated beams are obtained which can be used to assemble a pallet in the same way as conventional wooden pallets. The manufacture of the beams from pieces of cores each of which are preferably the same size can be done as an automatic process.

According to the invention the height of the core pieces used for said beams is preferably approximately the same or slightly smaller than the outer diameter thereof. This type of dimensioning is advantageous both with respect to the load- carrying capacity of the resulting pallet and the manageability of the same.

The cardboard surrounding the board pieces in the pallet is preferably corrugated board according to the invention, alternatively comprising corrugated layers and straight liner layers. It is preferred with respect to the rigidity of the beam that the corrugations run in the axial direction of the beam.

If the goods to be loaded are self-supporting, rigid boxes or similar packages, for instance, corresponding to the size of the pallet, the pallet can be comprised only of beams which are attached to each other crosswise. However, the pallet according to the invention is preferably provided with a covering sheet which is attached on top of the beams and comprised of rigid cardboard, whereby the pallet can also be used for loading smaller sized or loose goods such as sacks.

In order to make it easier to move the pallet, it is preferred to space the beams which are mutually parallel at least in one layer of the pallet, so that the pallet can be lifted by a lifting fork which is placed into the gaps of the pallet.

The pallet according to the invention can be assembled by using only glue which is separated from the pulp in the recycling process of the material. These adhesives include, for instance, the known so-called hot melt glues and cold glues. On the other hand, it is also possible to use rivets for ensuring the glue joints of the pallet.

According to the invention the pallet can be attached to the package it is carrying. The pallet and the package, such as a large paper sack, thus form a disposable package assembly the material of which is fully recyclable after use.

In the following the invention is described in more detail with the aid of the examples and with reference to the appended drawings where:

Fig. 1 shows a pallet is comprised of cross beams and a covering sheet, according to the invention,

Fig. 2 shows a single beam of the pallet as viewed from the top and partly cut open, Fig. 3 shows the side view of the same beam partly cut open.

Fig. 4 shows a half-finished beam where the board core pieces are placed in a row on the corrugated cardboard which is to be wrapped around them.

Fig. 5 shows a single piece of core which belongs to the beam, Fig. 6 shows the end of a finished single beam,

Fig. 7 shows, in an enlarged scale, a corner of a piece of corrugated cardboard used for the beam, and

Fig. 8 shows the filling of a large paper sack glued to the pallet. Fig. 1 shows pallet 1 according to the invention which is mainly meant for disposable use and which fully consists of recyclable material. Pallet 1 comprises covering sheet 2 made of rigid corrugated cardboard and beams 3 formed of cardboard and arranged crosswise in two layers under it. Covering sheet 2 and beams 3 are glued together by hot melt glue separated in the pulping phase of the recycling process. The size of pallet 1 is in the order of 0.5 - 1.5m x 0.5 x 1.5m and it is meant for carrying, for example, large paper sacks which weigh a few hundred kilos. Parallel beams 3 are spaced from each other in pallet 1 in such a way that the pallet can be moved by a lifting fork pushed between the beams.

The structure of beams 3 which are included in pallet l according to Fig. 1 is shown in Figs. 2 to 7. The beams employ tube-like board core pieces 4 according to Fig. 5 which are cut from board cores used as cores of paper rolls, for instance. Inner diameter d of core pieces 4 generally varies between about 75 to 100mm, the outer diameter D between about 85 to 180mm, the wall thickness of the jacket between about 2 to 15mm and height h between about 30 to 100m. Optimally, height h of core piece 4 is slightly smaller than or at the most about the same as outer diameter D.

Core pieces 4 can be -arranged in beam 3 in a row according to Fig. 4. The number of core pieces 4 in the beam can vary depending on the length of the beam, i.e., the dimensions of pallet 1, which is to be manufactured. If the desired length of the beam is not a multiple of outer diameter D of the core piece, a gap can be left in the middle of the row formed of core pieces 4. Other than that, it is preferred to glue the cores of the pieces in the row to each other from the sides thereof.

Core pieces 4 in beam 3 are surrounded by sheet of corrugated cardboard 6 which is provided with folds 5 corresponding to the edges of the beam, and wrapped around the beams. The outermost strips of sheet 6 are made to overlap on top of core pieces 4 according to Fig. 6 and joined together using said hot melt glue. The same glue is also used on all the contact surfaces between core pieces 4 and corrugated cardboard 6.

Sheet of corrugated cardboard 6 can alternatively be dimensioned so that the width of its outermost strips is only half of the width of beam 3. Thus beam 3 comprises a simple layer of corrugated cardboard where the edges of sheet 6 are situated against each other without overlapping each other as in Fig. 6. Corrugated cardboard 6 employed in beams 3 is formed of five overlapping layers, according to Fig. 7, of which the one in the middle and the outermost ones are straight liner layers 7 and the two others are corrugated layers 8. The corrugations of layers 8 run in the axial direction of beams 3.

With respect to the bearing capacity of pallet 1 it is essential that axes 9 of tube-like core pieces 4 (cf. Fig. 4) are placed in the pallet in the direction of the loading, i.e., perpendicular to the level of the pallet (covering sheet 2).

Fig. 8 shows pallet l according to Fig. 1 which carries large paper sack 10 filled with a powdery product or granulation. The filling of sack 10 is carried out while it is on pallet 1 and the sack can be glued to the pallet. Pallet 1 and the sack thus form together a disposable packaging unit which can be used as raw material of recycled pulp after the sack is emptied.

It is clear to those skilled in the art that different applications of the invention are not limited to the above- described examples but can vary within the appended Claims.

Claims

1 . A pallet (1) manufactured mainly of recyclable cardboard using tube-like board core pieces (4) which are situated in the pallet in such a way that their axes (9) are perpendicular to the level of the pallet, c h a r a c t e r i z e d in that the pallet (1) comprises beams (3) formed of parallel tube-like board core pieces (4) and the corrugated cardboard (6) surrounding them, the beams being attached to each other crosswise in two overlapping layers in the pallet.

2. A pallet according to Claim 1, c h a r a c t e r i z e d in that the height (h) of the core pieces (4) is essentially the same or smaller than their outer diameter (D).

3. A pallet according to Claim l or 2, c h a r a c t e r i z e d in that the beams (3) are made of corrugated cardboard (6) so that the corrugations run in the axial direction of the beam.

4. A pallet according to Claim 3, c h a r a c t e r i z e d in that the corrugated cardboard (6) comprises alternatively corrugated layers (8) and straight liner layers (7).

5. A pallet according to any of the preceding Claims, c h a r a c t e r i z e d in that, besides the layers formed of the beams (3), the pallet (1) comprises a covering sheet (2) of rigid cardboard.

6. A pallet according to any of the preceding Claims, c h a r a c t e r i z e d in that, at least in one of the layers, the mutually parallel beams (3) are spaced from each other so that the pallet (1) can be lifted by a lifting fork pushed into the gaps of the beams.

7. A pallet according to any of the preceding Claims, c h a r a c t e r i z e d in that the parts of the pallet (l) are attached to each other by glue separated in the recycling process of material.

8. A pallet according to any of the preceding Claims, c h a r a c t e r i z e d in that the pallet (1) is attached to the large paper sack (10) it is carrying.

9. A pallet according to Claim 8, c h a r a c t e r i z e d in that a large paper sack (10) is glued to the pallet (1).